Characterisation of microbunching instability with 2D Fourier analysis.

The optimal performance of high-brightness free-electron lasers (FELs) is limited by the microbunching instability, which can cause variations in both the slice energy spread and longitudinal profile of electron beams. In this paper, we perform 2D Fourier analysis of the full bunch longitudinal phase space, such that modulations in both planes can be studied simultaneously. Unlike the standard 1D analysis, this method is able to reveal modulations in a folded phase space, which would otherwise remain uncovered. Additionally, the plasma oscillation between energy and density modulations is also revealed by this method. The damping of the microbunching instability, through the use of a laser heater, is also analysed with this technique. We confirm a mitigation of the amplitude of modulation and a red-shift of the microbunching frequency as the energy spread added increases. As an outcome of this work, a systematic experimental comparison of the development of the instability in the presence of different compression schemes is here presented for the first time.

An atypical case of pulmonary embolism from a jugular vein.

Neck venous malformations and their potentially life-threatening complications are rarely reported in the available literature. Cases of aneurysmal or hypo-plastic jugular vein thrombosis associated with systemic embolization have not been frequently reported. We present the case of a 60-year-old male, without any known risk factors for thromboembolic disease, admitted for sudden onset dyspnea. The physical examination was remarkable for a right lateral cervical mass, expanding with Valsalva maneuver. Thoracic CT with contrast established the diagnosis of bilateral pulmonary embolism and raised the suspicion of superior vena cava and right atrial thrombosis. Bedside transthoracic echocardiography confirmed the presence of a large right atrial thrombus, with intermittent protrusion through the tricuspid valve. Systemic thrombolysis with Alteplase was initiated shortly after diagnosis, in parallel with unfractionated heparin, with complete resolution of the intracavitary thrombus documented by echocardiography. The patient showed significant improvement in symptoms and was later started on oral anticoagulation. Computed vascular tomography of the neck was performed before discharge, showing hypoplasia of the left internal jugular vein and aneurismal dilation of the contralateral internal jugular vein, without thrombosis. There were no identifiable systemic causes for thrombosis. Surgical resection of the aneurismal jugular vein was excluded, because of its potential to cause intracranial hypertension. The preferred therapeutic option in this case was long-term oral anticoagulation. Learning points: Internal jugular venous malformations, such as aneurisms or hypoplasia, could be associated with an increased risk of thrombosis and major embolic events. Systemic thrombolysis can be an efficient solution in cases of pulmonary embolism with right heart thrombosis. Multimodality imaging is greatly valuable in clarifying the diagnosis of atypical cases.

Coherent THz Emission Enhanced by Coherent Synchrotron Radiation Wakefield.

We demonstrate that emission of coherent transition radiation by a ∼1 GeV energy-electron beam passing through an Al foil is enhanced in intensity and extended in frequency spectral range, by the energy correlation established along the beam by coherent synchrotron radiation wakefield, in the presence of a proper electron optics in the beam delivery system. Analytical and numerical models, based on experimental electron beam parameters collected at the FERMI free electron laser (FEL), predict transition radiation with two intensity peaks at ∼0.3 THz and ∼1.5 THz, and extending up to 8.5 THz with intensity above 20 dB w.r.t. the main peak. Up to 80-µJ pulse energy integrated over the full bandwidth is expected at the source, and in agreement with experimental pulse energy measurements. By virtue of its implementation in an FEL beam dump line, this work promises dissemination of user-oriented multi-THz beamlines parasitic and self-synchronized to EUV and x-ray FELs.

The FERMI free-electron lasers.

FERMI is a seeded free-electron laser (FEL) facility located at the Elettra laboratory in Trieste, Italy, and is now in user operation with its first FEL line, FEL-1, covering the wavelength range between 100 and 20 nm. The second FEL line, FEL-2, a high-gain harmonic generation double-stage cascade covering the wavelength range 20-4 nm, has also completed commissioning and the first user call has been recently opened. An overview of the typical operating modes of the facility is presented.

Evaluation of right ventricular function performed by 3D-echocardiography in scleroderma patients.

The impairment of the right ventricle (RV) in systemic sclerosis (SSc) is usually related to pulmonary arterial hypertension (PAH). New echocardiographic techniques, such as 3-dimensional echocardiography (3DE) and 2-dimensional speckle tracking (2DSTE), allow an accurate evaluation of the RV function. The aim of this study was to evaluate the RV function using 3DE and 2DSTE in SSc patients with no history of heart disease and no PAH. Forty-five SSc patients, 42 females and 3 males, 28 with limited cutaneous SSc (lcSSc) and 17 with diffuse cutaneous SSc (dcSSc), were studied. Forty-three age- and gender-matched healthy subjects were enrolled as controls. All of them underwent a 3DE and 2DSTE ecocardiographic evaluation of the RV function. Systolic pulmonary arterial pressure (sPAP) and total pulmonary vascular resistance (tPVR) were also estimated by power doppler. RV echocardiographic parameters were compared in the different subsets of SSc patients. A statistical analysis was performed by t-test, ANOVA and multiple logistic regression. RV areas in 2DSTE and volumes in 3DE were higher and RV function parameters were reduced in SSc patients compared with controls. Also sPAP and tVPR were higher, but they did not reach pathological values. Echocardiographic alterations were more pronounced in patients with lcSSc. 3DE and 2DSTE echocardiography allowed us to detect morphological and functional alterations of the RV in a group of SSc patients with no clinical signs of heart disease and no PAH. These patients had significantly higher sPAP and tPVR than healthy controls without reporting values compatible with PAH. These data suggest that RV alterations are related to a pressure overload rather than to an intrinsic myocardial involvement in SSc.

One-and-a-half ventricle repair as a surgical alternative to Fontan revision in an adult.

We report a case of a young man with hypoplastic right ventricle, who presented with recurrent untreatable arrhythmias after a Bjork Fontan procedure in infancy. He underwent one-and-a-half ventricle repair as an alternative surgery to Fontan revision.

Ultrasound and radiology surrogate endpoints in pharmacological studies.

Cardiovascular studies investigating therapeutic intervention with clinical endpoints are costly due to the need for considerable duration and large number of patients, or both. Therefore, for evaluation of novel cardiovascular drug efficacy, surrogate endpoints are used. Cardiovascular imaging endpoints have proven their worth. Sometimes the relevance of imaging is questioned and other methods are suggested instead. There is also some confusion about the strengths of imaging endpoints. The aim of the present paper is to review ultrasound and radiology imaging techniques as surrogate endpoints in pharmacological trials.

Recommendations for transoesophageal echocardiography: update 2010.

Transoesophageal echocardiography (TOE) is a standard and indispensable technique in clinical practice. The present recommendations represent an update and extension of the recommendations published in 2001 by the Working Group on Echocardiography of the European Society of Cardiology. New developments covered include technical advances such as 3D transoesophageal echo as well as developing applications such as transoesophageal echo in aortic valve repair and in valvular interventions, as well as a full section on perioperative TOE.

Acute thrombosis of mechanical mitral valve prosthesis: echo-Doppler diagnosis and successful treatment with systemic thrombolysis.

The case of a 72-year old patient with acute heart failure due to thrombosis of the mechanical mitral prosthesis is presented. The diagnosis was made by transthoracic echocardiography. The patient refused reoperation, and systemic thrombolysis was administered. After thrombolytic infusion we observe the disappearance of the echocardiographic signs of thrombosis, with concomitant improvement of symptoms.

Relation between early mitral regurgitation and left ventricular thrombus formation after acute myocardial infarction: results of the GISSI-3 echo substudy.

OBJECTIVE: To evaluate the prevalence and correlates of left ventricular thrombosis in patients with acute myocardial infarction, and whether the occurrence of early mitral regurgitation has a protective effect against the formation of left ventricular thrombus. DESIGN AND SETTING: Multicentre clinical trial carried out in 47 Italian coronary care units. PATIENTS AND METHODS: 757 patients from the GISSI-3 echo substudy population with their first acute myocardial infarct were studied by echocardiography at 24-48 hours from symptom onset (S1), at discharge (S2), at six weeks (S3), and at six months (S4). The diagnosis of left ventricular thrombosis was based on the detection of an echo dense mass with defined margins visible throughout the cardiac cycle in at least two orthogonal views. RESULTS: In 64 patients (8%), left ventricular thrombosis was detected in one or more examinations. Compared with the remaining 693 patients, subjects with left ventricular thrombosis were older (mean (SD) age: 64.6 (13.0) v 59.8 (11.7) years, p < 0.005), and had larger infarcts (extent of wall motion asynergy: 40.9 (11.5)% v 24.9 (14)%, p < 0.001), greater depression of left ventricular ejection fraction at S1 (43.3 (6.9)% v 48.1 (6.8)%, p < 0.001), and greater left ventricular volumes at S1 (end diastolic volume: 87 (22) v 78 (18) ml/m(2), p < 0.001; end systolic volume: 50 (17) v 41 (14) ml/m(2), p < 0.001). The prevalence of moderate to severe mitral regurgitation on colour Doppler at S1 was greater in patients who had left ventricular thrombosis at any time (10.2% v 4.2%, p < 0.05). On stepwise multiple logistic regression analysis the only independent variables related to the presence of left ventricular thrombosis were the extent of wall motion asynergy and anterior site of infarction. CONCLUSIONS: Left ventricular thrombosis is not reduced, and may even be increased, by early moderate to severe mitral regurgitation after acute myocardial infarction. The only independent determinant of left ventricular thrombosis is the extent of the akinetic-dyskinetic area detected on echocardiography between 24-48 hours from symptom onset.

Feasibility and clinical value of "intelligent" compression and digital storage of transthoracic echocardiograms in day-to-day practice.

BACKGROUND: The aim of this study was to assess the clinical concordance of expert cardiologists' interpretation of echocardiographic studies recorded on Super-VHS videotape or stored in magneto-optical disk, as well as the feasibility and clinical value of intelligent compression and digital storage of echocardiographic data as cine-loops and still-frames for interpretation of transthoracic echocardiographic images in clinical practice. METHODS: All clinical cardiologists experienced in echocardiography in our department (n = 10) reported on a standardized worksheet checklist the echocardiographic data of 7 consecutive patients (140 reports), and recorded them on videotape or magneto-optical disks to compare the interpretation of videotaped studies, acquired in the usual way, with clinically compressed studies stored to magneto-optical disks using a standard (Italian Society of Echocardiography) image acquisition protocol. RESULTS: The time interval between analog and digital study readings was 50 +/- 15 days. Except for tricuspid valve regurgitation grading (k = 0.28) and for left ventricular global hypokinesia (k = 0.32), the intraobserver agreement in the interpretation of the 3290 cardiovascular morphological and functional findings found on analog and digitally stored images was good (k value ranging from 0.66 to 1.00). The wall motion score index was 1.56 +/- 0.53 when interpreting analog studies, and 1.52 +/- 0.54 on digital studies (p = 0.35). Conversely, the interobserver variability of the wall motion score index (Gini index ranging from 0 to 0.80) was significantly lower when interpreting studies stored digitally than when analog ones were examined (0.48 +/- 0.021 and 0.52 +/- 0.023 respectively, p = 0.006). In comparison to videotape recordings, digital storage of echocardiographic studies significantly shortened the time to image access for study review (327 +/- 62 and 30 +/- 4 s, respectively, p < 0.0001) and the reading time (600 +/- 300 and 540 +/- 300 s respectively, p = 0.034), rendered study accessibility easier (difficult or good: 73 vs 43% of observers, fast or optimal: 27 vs 57% of observers respectively, p = 0.0011) and improved the recorded image quality perception (poor: 25 vs 10% of observers, sufficient or good: 75 vs 90% of observers respectively, p = 0.022), without loss of study completeness (insufficient: 18 vs 17% of observers, adequate or complete: 82 vs 83% of observers, respectively; p = NS). Finally, from September 1, 1999, digital storage has become routine practice for patients admitted to our Department. By December 31, 1999, 411 echo studies had been stored: 7 +/- 3 cine-loop/study, 32 +/- 18 frames/cine-loop, and 3 +/- 2 still-frames/study. The average amount of memory needed for storage was 18.6 +/- 11.9 MB/study. CONCLUSIONS: Clinical compression of echocardiographic studies seems to be an accurate summary of the complete examination recorded to videotape for the assessment of patients admitted in the coronary care unit. In addition, digitally stored studies allow a significant improvement in the interobserver reproducibility of wall motion score assessment.

[Reporting echocardiography exams with the G8-Cardio ANMCO software]. / Refertazione dell'esame ecocardiografico con il software G8-Cardio ANMCO.

BACKGROUND: The availability of a common computerized program for echocardiographic study archiving and reporting at national and/or international level could make it possible to standardize the echo reports of different echocardiographic laboratories, and to use the wealth of data thus obtainable with echocardiography, and to exploit its capillary territorial distribution, with the aim of collecting echocardiographic data in a standard format for epidemiological, scientific and administrative purposes. METHODS: To develop such a software, an ad hoc joint National Association of Hospital Cardiologists and Italian Society of Echocardiography task force worked in conjunction with the Italian Branch of Agilent Technologies to standardize the phraseology of accepted echocardiographic terms and of the quantitative parameters derived from transthoracic and transesophageal echocardiographic examination at rest as well as during exercise and pharmacological stress, and to develop an ad hoc software. This echocardiographic study archiving and reporting program is part of the whole G8-Cardio ANMCO software developed to computerize the whole cardiological chart. The software has been developed by Agilent Technologies to provide a fast, easy-access and easy to use report generator for the non-computer specialist using DBMS Oracle 7.3 database and Power Builder 5.0 to develop a user-friendly interface. RESULTS: The number of qualitative and quantitative variables contained in the program is 733 for echocardiography at rest, while it depends on the stressor and on the length of the examination for the stress echo (dipyridamole 214-384, dobutamine 236-406, exercise 198-392). The program was tested and refined in our laboratory between November 1999 and May 2000. During this time period, 291 resting and 56 stress echocardiographic studies were reported and recorded in a database. On average, each resting echocardiographic study lasting 10 +/- 4 (range 5-17) min was recorded using 50 +/- 11 (range 33-67) variables and 41,566 bytes of hard-disk memory space. Stress echocardiographic studies, each lasting 7 +/- 5 (range 5-21) min, were recorded using 143 +/- 74 (range 38-194) variables and 38,531 bytes of hard-disk memory space. CONCLUSIONS: To our knowledge this software represents the first experience of a common computerized program for echo archiving and reporting carried out at national level.

Specialty-related differences in the epidemiology, clinical profile, management and outcome of patients hospitalized for heart failure; the OSCUR study. Oucome dello Scompenso Cardiaco in relazione all'Utilizzo delle Risore.

AIMS: This study was designed to identify potential specialty-related differences in the epidemiology, clinical profile, management and outcome of patients hospitalized for congestive heart failure in departments of cardiology or internal medicine. METHODS AND RESULTS: From 1 July to 31 December 1998, we prospectively recorded epidemiological and clinical data from patients with congestive heart failure consecutively admitted to 11 departments of cardiology and 12 departments of internal medicine in Liguria, a northern area of Italy. The overall study population included 749 patients; 22% were treated by cardiologists and 78% by internists (P<0.0001). Patients managed by cardiologists were more likely to undergo echocardiography (92% vs 37%), Holter monitoring (25% vs 3%) and exercise stress testing (20% vs 0.5%) than those managed by internists (P=0.001). At discharge, patients treated by cardiologists were more likely to be prescribed beta-blockers (41% to 4%) and ACE inhibitors (100% to 74%) than those treated by internists (P<0.0001), and the latter medication at higher dosages by cardiologists than internists. In addition, patients followed by cardiologists were younger (70+/-9 to 79+/-1 years;P<0.0001), more likely to be male (61% to 50%;P=0.011) and to have coronary artery disease (57% to 45%;P<0.006) than those followed by internists. Conversely, patients followed by internists were more likely to have diabetes, chronic obstructive pulmonary disease, atrial fibrillation and renal failure (P<0.03). In the overall study population, 53 patients (7%) died during hospitalization. Patients treated by cardiologists had a mortality not significantly different from that of patients treated by internists (10% and 6%, respectively;P=0.067), although congestive heart failure was more severe on admission in patients treated by cardiologists. CONCLUSION: Cardiologists follow published guidelines for congestive heart failure more strictly than internists, but treat a smaller number of patients who are younger, have more severe congestive heart failure and fewer co-morbidities than those managed by internists.

Dynamic left ventricular outflow tract obstruction: an unusual mechanism mimicking anterior myocardial infarction with cardiogenic shock.

Cardiogenic shock is a frequent and threatening complication in the course of acute myocardial infarction. Besides the well known causes (left ventricular failure, acquired interventricular defect, papillary muscle rupture, free wall rupture) other less frequent mechanisms recognize a functional substrate. The recognition of such mechanisms makes us to revert to the treatments with completely different prognostic implications. In our Coronary Care Unit we encountered, in a period of 12 months, 4 patients who presented clinical, electrocardiographic and/or echographic signs and symptoms of acute myocardial infarction, with different degrees of heart failure up to cardiogenic shock. Only 1 patient showed a severe stenosis of the left anterior descending coronary artery and a significant creatine kinase reduction. Left ventriculography, performed at admission, was unable to disclose the true mechanism of clinical presentation. Only a thorough echographic examination disclosed the presence of a dynamic left ventricular outflow tract obstruction as the cause of heart failure culminating in cardiogenic shock. Once recognized, pathophysiological treatment (administration of beta-blockers and withdrawal of vasodilators, inotropic drugs and intra-aortic balloon pump) led to a dramatic improvement, with an almost complete left ventricular function recovery. Left ventricular outflow tract obstruction is a mechanism that can lead to severe heart failure as a complication of an acute myocardial infarction. Conversely such a mechanism can be precipitated by other causes (hypotension, hypovolemia, especially in hypertensive patients) and can mimic an acute myocardial infarction. Its incidence is not negligible: in our Coronary Care Unit it accounted for about 15% of all cases of myocardial infarction requiring inotropic support. An accurate echocardiographic examination is mandatory even after coronary angiography, and always permits the physician to select the appropriate therapy.

Heterogeneity of left ventricular remodeling after acute myocardial infarction: results of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico-3 Echo Substudy.

BACKGROUND: Left ventricular (LV) remodeling after acute myocardial infarction has still to be clarified in the thrombolytic era. METHODS: To evaluate timing and the magnitude and pattern of postinfarct LV remodeling, a subset of 614 patients enrolled in the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico-3 Echo Substudy underwent serial 2-dimensional echocardiograms at 24 to 48 hours from symptom onset (S1), at hospital discharge (S2), at 6 weeks (S3), and at 6 months (S4) after acute myocardial infarction. RESULTS: During the study period the end-diastolic volume index (EDVi) increased (P <.001) and wall motion abnormalities (%WMA) decreased (P <.001), whereas ejection fraction (EF) remained unchanged. Nineteen percent of patients showed a > 20% increase in EDVi at S2 compared with S1 (severe early dilation), and 16% of patients showed a > 20% dilation at S4 compared with S2 (severe late dilation). Independent predictors of severe in-hospital LV dilation were relatively small EDVi (odds ratio [OR] 0.961, 95% confidence interval [CI] 0.947-0.974, P =.0001) and relatively large %WMA (OR 1.030, 95% CI 1.013-1.048, P =.0005). Similarly, smaller predischarge EDVi (OR 0.975, 95% CI 0. 963-0.987, P =.0001), greater %WMA (OR 1.026, 95% CI 1.008-1.045, P =.0042), and moderate to severe mitral regurgitation (OR 2.261, 95% CI 1.031-4.958, P = 0.0417) independently predicted severe late dilation. Importantly, 92% of the patients with severe early dilation did not have further dilation at S4, and 91% of patients with severe late dilation did not have in-hospital dilation. EF was unchanged over time in patients with early dilation, whereas it significantly decreased in those with late dilation. CONCLUSIONS: Although in-hospital LV enlargement is not predictive of subsequent dilation and dysfunction, late remodeling is associated with progressive deterioration of global ventricular function over time: patients with extensive %WMA and not significantly enlarged ventricular volume before discharge are at higher risk for progressive dilation and dysfunction.

[The SCOOP II trial in heart failure]. / Lo studio SCOOP II (Scompenso nell'Ospedalizzazione Pubblica): proposta di un modello.

BACKGROUND: The aim of this study was to evaluate the effectiveness of a health education intervention aimed at improving therapeutic compliance and quality of life of patients with chronic heart failure (CHF). In this 1100 bed Community hospital 97% of patients with CHF admitted to the Internal Medicine Unit have a high rate of readmission, mortality and negative quality of life. METHODS: Two hundred patients (123 males, 77 females, mean age 75 years) were enrolled and randomized. CHF patients admitted to the Internal Medicine Unit were randomly assigned to usual care (n=100) or intervention group (n=100), which consisted of a nurse-guided education program, facilitated telephone communication and regularly scheduled follow-up visits with an internist. The primary endpoints were quality of life and quality of service improvement, and improved compliance with the heart failure guidelines. All patients were submitted to echocardiography. RESULTS: Ejection fraction is available for 87% of them. Baseline quality of life is similar in both groups. Final data will be available after April 2001.